1. Field of the Invention
The present invention pertains to the art of illumination and, more particularly, to a lighting system employing bidirectional optics for use in connection with illuminating one or more shelves of a product display unit.
2. Discussion of the Prior Art
Utilizing lighting units to illuminate products displayed on shelves of display cabinets or the like is widely known in the art. For instance, it is common to attach one or more lighting fixtures within a refrigerated display cabinet of a supermarket in order to illuminate food products supported on vertically spaced shelves of the cabinet. Most commonly, fluorescent lighting is used for this purpose, although it has been known to utilize incandescent lighting.
Regardless of the specific type of lighting source utilized, the additional source of lighting can advantageously enhance the visibility of food products for consumers. Typically, the lighting units are mounted to an upper cabinet panel or directly beneath shelves of the display unit to illuminate food items placed on a lower shelf. Even in the case of display units used to support other products which do not require a dedicated refrigeration system, illuminating the products are still considered desirable.
When contemplating the retrofitting of display units which were not originally designed for use with lighting systems, consideration must be given to numerous factors, including reasonable cost constraints, sizing parameters, the manner in which heat from the lighting system will affect products stored on shelves of the display and the aesthetics of the final is overall unit. In general, little emphasis has been placed in the past on retrofitting food display cabinets or the like with lighting systems. That is, new lighting systems may be designed when production is changed on a refrigerated food display cabinet, but little or no efforts have been undertaken to retrofit existing food display cabinets with more efficient lighting systems or to even add lighting systems to non-refrigerated food product displays.
To address these and other concerns, the present applicant developed a modular lighting system for a product display unit which can be easily retrofitted to standard food display units and that can be readily implemented in the manufacturing of new display units, while having an aesthetic design so as to be pleasing to consumers. This prior proposed modular lighting arrangement is now covered by U.S. Pat. No. 6,179,434. One main purpose achieved by this prior arrangement is to illuminate products arranged at a frontal section of each of the product display shelves. However, it is often necessary to enhance the lighting of products supported on other portions of a display shelf, including a rearmost shelf portion. For instance, in supermarket display units utilized to carry meat products, various different types of meats or cuts are typically arranged from a front portion of a shelf to a rear portion thereof. In such an arrangement, it would be desirable to provide a substantially uniform lighting arrangement between the various meat sections. This problem could be addressed by providing various lighting units dedicated for lighting different portions of each shelf. Obviously, such an arrangement is not very cost effective or efficient, particularly in the environment of refrigerated display units wherein the lighting units actually produce heat which is detrimental to the cooling operation.
Based on the above, there exists a need in the art for a lighting system which will enable a minimum number of lighting units to effectively illuminate essentially entire shelving portions of a product display unit. More particularly, there exists a need in the art to provide such an improved lighting system while still enabling the lighting units to be supported at frontal shelf portions.
In accordance with the present invention, a modular lighting system is provided for illuminating products supported upon various vertically arranged shelves of a display unit. In accordance with an aspect of the invention, the lighting system includes a housing which is attached to a front end portion of a first shelf, with the housing including at least one transparent panel which permits an internal illumination source to light products supported upon at least one of the first shelf, a shelf arranged directly above the first shelf and a shelf disposed directly below the first shelf. Most preferably, the light illuminating from the housing supported by the first shelf is directed in such a manner so as to effectively, entirely illuminate product support surfaces associated with both the first shelf and the shelf directly below such that the display of products supported from the front to the back of these shelves is enhanced.
In accordance with the invention, this front-to-back lighting function can be achieved in various ways, such as by employing direct, reflective and refractive lighting techniques. The lighting system of the present invention can be readily retrofitted to existing display units or incorporated into newly manufactured display units. In addition, the lighting system is designed to be efficient in operation and structured to enhance the emission of light therefrom.
Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments thereof when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.